In a network architecture in the prior art, connections of networks, exchange of information, and monitoring and management in networks largely depend on an Internet Protocol (IP) address of a device. A user uses an IP address to access a network, where the IP address is allocated to the user by a server in the network based on the IP protocol. Information is exchanged between different users by using their respective IP addresses, and an administrator in the network uses IP addresses to monitor and manage the network.
However, as required by flat management, network devices connected to an access device in a network become smaller in size and keeps growing in number. If an IP address is allocated to each network device, limited IP address resources will become deficient. Therefore, operators put forward a network architecture in which an IP address is not configured for a network device connected to an access device in a network, so as to save IP address resources. Connections of networks, exchange of information, and monitoring and management of networks in the prior art are performed mostly based on IP addresses. Consequently, a network device that does not have an IP address and is connected to an access device in a network can hardly implement IP address based-communication.